Field of the Invention
The present invention relates to a battery block holding a plurality of battery cells and a secondary battery module.
Background Art
JP 2001-6643 A, for example, shows a power supply device including a holder case 2 containing a plurality of power supply modules (battery cells) 1 connected in series. The holder case 2 includes upper and lower cover case 2A and an intermediate case 2B disposed between the upper and lower cover case 2A, and is configured so that the power supply modules 1 are sandwiched and fixed between the cover case 2A and the intermediate case 2B to be included internally at a fixed position. Then these plurality of power supply modules have output terminals connected in series.
Since the power supply device described in the above patent document is configured to include a large number of power supply modules (corresponding to battery cells) 1 internally at a fixed position while sandwiching them between the cover case 2A and the intermediate case 2B for fixing, the fixing state of the power supply modules is not stable and each power supply module may move slightly due to vibrations or the like. The power supply modules may have different dimensions such as a diameter, following their tolerance during manufacturing, and so a space may be generated between the power supply modules and the cover case or the intermediate case during sandwiching for fixing, which may be another factor to move the power supply modules slightly due to vibrations or the like. Then, a load may be applied to a welding part of a conductive member connecting the output terminals due to vibrations or the like.
In the thus configured battery block, when the plurality of power supply modules, e.g., cylindrical battery cells, aligned and fixed are sandwiched between two members, a space between the battery cells and the two members may vary with each battery cell having a different diameter, and then the battery cells may move slightly between the two members due to the space. The plurality of battery cells are connected at their electrodes with conductive plates or the like, and in the case of fixing the conductive plates by welding, a load will be applied to the welding part, which may cause a defect for connection. When the connected part is disconnected, the storage device loses its function unfortunately.